| Project/Area Number |
07455223
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Building structures/materials
|
|---|
| Research Institution | KYOTO UNIVERSITY |
|---|
Principal Investigator |
NAKASHIMA Masayoshi Kyoto Univ., Disaster Prevention Research Institute, Associate Professor, 防災研究所, 助教授 (00207771)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
IWAI Satoshi Kyoto Univ., Disaster Prevention Research Institute Research Associate, 防災研究所, 助手 (60184850)
NONAKA Taijiro Kyoto Univ., Disaster Prevention Research Institute Professor, 防災研究所, 教授 (60027224)
|
|---|
| Project Period (FY) |
1995 – 1996
|
| Project Status |
Completed (Fiscal Year 1996)
|
| Budget Amount *help |
¥5,700,000 (Direct Cost: ¥5,700,000)
Fiscal Year 1996: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1995: ¥3,800,000 (Direct Cost: ¥3,800,000)
|
|---|
| Keywords | Reliability-Based Design / Steel Building Frame / Plastic Deformation Demand / Variation / Monte-Carolo Simulation |
|---|
| Research Abstract |
In seismic design, plastic deformations of structures and structural members play an important role, but the quantities are known to vary very significantly. In this course, seismic design incorporated with the reliability concept is of serious consideration. The objective of this project is (1) to develop a simple, systematic method to estimate the degree of variation of plastic deformations demanded of steel building structures and their elements and (2) to provide a guideline as to the variation to be considered in seismic design. A analytic procedure consisting of the following steps was developed ; (1) to select likely collapse mechanisms by use of the Symplex method, (2) to estimate plastic hinge rotations by solving the stiffness matrix corresponding to the instant of a collapse mechanism, and (3) to estimate the variation of the obtained plastic hinge rotations by the application of the FOSM method. Several steel building frames were analyzed for the variation of their plastic hinge rotations, where the proposed method and Monte-Carlo simulation were employed. It was found that, for an coefficient of variation of 0.1 assigned for the member plastic moment capacities, the coefficient of variation of the ultimate load was about 0.03, whereas the coefficient of variation of the member plastic rotations ranged from 0.3 to as much as 0.7. The finding indicates that the member plastic deformation can vary very significantly even for a moderate variation of member strength and that a large margin of safety has to be introduced if seismic design is formed to consider the plastic deformation, in terms of both the demand and capacity, in an explicit manner.
|
